Cell re-selection in a cellular telecommunications network

Abstract

According to an aspect of the present disclosure, there may be provided a method in a wireless cellular telecommunications device camped on a serving cell, the device storing a parameter obtained by decoding system information of a first cell. The method comprises: measuring an attribute of a signal received from a candidate cell; and, evaluating the candidate cell for re-selection based on the measured attribute according to a priority-based re-selection algorithm irrespective of the stored parameter. The parameter indicates a minimum required received signal code power. A device and computer readable medium are also provided.

The invention claimed is: 
     
       1. A method in a wireless cellular telecommunications device camped on a serving cell, the method comprising:
 storing a parameter obtained by decoding system information of a first cell; 
 measuring an attribute of a signal received from a candidate cell; and, 
 evaluating the candidate cell for re-selection based on the measured attribute according to a priority-based re-selection algorithm irrespective of the stored parameter, wherein the stored parameter indicates a minimum required received signal code power. 
 
     
     
       2. A method according to  claim 1 , further comprising performing re-selection from the serving cell to the candidate cell based on the evaluation. 
     
     
       3. A method according to  claim 1 , wherein evaluating the candidate cell includes at least:
 acquiring system information of the candidate cell, the system information including a candidate cell parameter; 
 determining if the measured attribute exceeds the candidate cell parameter by a predetermined amount; and, 
 if the measured attribute exceeds the candidate cell parameter by a predetermined amount, performing re-selection to the candidate cell. 
 
     
     
       4. A method according to  claim 3  in which the predetermined amount is 0 dB. 
     
     
       5. A method according to  claim 1 , wherein evaluating the candidate cell for re-selection includes at least:
 determining if the measured attribute exceeds a predetermined default value; and, 
 if the measured attribute fails to exceed the predetermined default value, determining that the candidate cell does not meet re-selection requirements. 
 
     
     
       6. A method according to  claim 1 , in which the measured attribute is received signal code power (RSCP). 
     
     
       7. A method according to  claim 1 , in which the candidate cell is a UTRAN cell. 
     
     
       8. A method according to  claim 1 , in which the serving cell is a GERAN cell. 
     
     
       9. A method according to  claim 1 , further comprising:
 measuring an attribute of a signal received from a second cell; and, 
 evaluating the second cell for re-selection based on the measured attribute and the stored parameter according to a ranking algorithm. 
 
     
     
       10. A method according to  claim 1 , in which the serving and candidate cells are of the same wireless radio network. 
     
     
       11. A method according to  claim 1 , in which the serving and candidate cells are of different wireless radio networks. 
     
     
       12. A wireless cellular telecommunications device adapted to:
 camp on a serving cell; 
 store a parameter obtained by decoding system information of a first cell; 
 measure an attribute of a signal received from a candidate cell; and, 
 evaluate the candidate cell for re-selection based on the measured attribute according to a priority-based re-selection algorithm irrespective of the stored parameter, wherein the stored parameter indicates a minimum required signal code power. 
 
     
     
       13. A device according to  claim 12 , further adapted to perform re-selection from the serving cell to the candidate cell based on the evaluation. 
     
     
       14. A device according to  claim 12  wherein evaluating the candidate cell includes at least:
 acquiring system information of the candidate cell, the system information including a candidate cell parameter; 
 determining if the measured attribute exceeds the candidate cell parameter by a predetermined amount; and, 
 if the measured attribute exceeds the candidate cell parameter by a predetermined amount, performing re-selection to the candidate cell. 
 
     
     
       15. A device according to  claim 14  in which the predetermined amount is 0 dB. 
     
     
       16. A device according to  claim 12  wherein evaluating the candidate cell for re-selection includes at least:
 determining if the measured attribute exceeds a predetermined default value; and, 
 if the measured attribute fails to exceed the predetermined default value, determining that the candidate cell does not meet re-selection requirements. 
 
     
     
       17. A device according to  claim 12  in which the measured attribute is received signal code power (RSCP). 
     
     
       18. A device according to  claim 12  in which the candidate cell is a UTRAN cell. 
     
     
       19. A device according to  claim 12  in which the serving cell is a GERAN cell. 
     
     
       20. A device according to  claim 12  further adapted to:
 measure an attribute of a signal received from a second cell; and, 
 evaluate the second cell for re-selection based on the measured attribute and the stored parameter according to a ranking algorithm. 
 
     
     
       21. A device according to  claim 12  in which the serving and candidate cells are of the same wireless radio network. 
     
     
       22. A device according to  claim 12  in which the serving and candidate cells are of different wireless radio networks. 
     
     
       23. A computer-readable storage medium having stored thereon instructions which can be executed by a device to:
 camp on a serving cell; 
 store a parameter obtained by decoding system information of a first cell; 
 measure an attribute of a signal received from a candidate cell; and, 
 evaluate the candidate cell for re-selection based on the measured attribute according to a priority-based re-selection algorithm irrespective of the stored parameter, wherein, the stored parameter indicates a minimum required signal code power.